BH1721FVC-TR Rohm Semiconductor, BH1721FVC-TR Datasheet

Page 1

... Ambient Light Sensor IC Series Digital 16bit Serial Output Type Ambient Light Sensor IC BH1721FVC ●Descriptions BH1721FVC is an digital Ambient Light Sensor IC for I light data for adjusting LCD and Keypad backlight power of Mobile phone possible to detect wide range at High resolution 65528 lx ). ●Features bus Interface ( Mode Support, Slave Address : "0100011" ) ...

Page 2

... BH1721FVC ●Electrical Characteristics ( VCC = 3.0V, DVI = 3.0V 25℃, unless otherwise noted ) Parameter Supply Current Powerdown Current Peak Wave Length Measurement Accuracy Dark ( Sensor out H-Resolution Mode Resolution L-Resolution Mode Resolution H-Resolution Mode Measurement Time L-Resolution Mode Measurement Time Incandescent / Fluorescent Sensor out ratio DVI Input ‘ ...

Page 3

... BH1721FVC ●Reference Data 1.2 1.0 0.8 0.6 0.4 0.2 0.0 400 500 600 700 800 900 1000 1100 Wavelength [ nm ] Fig.1 Spectral Response 1.2 1 1pin 0 0.6 0 0.2 0 -90 -60 - Angle [ deg ] Fig.4 Directional Characteristics 1 1.2 1 0.8 0.6 0.4 0.2 0 -40 - 100 Ta [ ℃ ] Fig.7 Measurement Result ...

Page 4

... BH1721FVC ●Block Diagram PD ●Block Diagram Descriptions ・PD Photo diode with approximately human eye response. ・AMP Integration-OPAMP for converting from PD current to Voltage. ・ADC AD converter for obtainment Digital 16bit data. 2 ・Logic + I C Interface Ambient Light Calculation and I Data Register → This is for registration of Ambient Light Data. Initial Value is "0000_0000_0000_0000". ...

Page 5

... Auto-Resolution mode selects measurement mode automatically determined after 16ms (typ.) passes from measurement start. If BH1721FVC judges that current illuminance is more than 4000 lx, then Data is output at L-resolution mode, else Data is output after 120ms(typ.) from measurement start at H-resolution mode. Please refer below flow chart. ...

Page 6

... BH1721FVC ●Timing chart for VCC and DVI power supply sequence 2 DVI bus reference voltage terminal. And it is also asynchronous reset terminal necessary to set to ‘L’ after VCC is supplied. In DVI 'L' term, internal state is set to Power Down mode. 1) Recommended Timing chart1 for VCC and DVI supply. ...

Page 7

... BH1721FVC ●Measurement sequence example from "Write instruction" to "Read measurement result" ex1) Continuously Auto-resolution mode from Master to Slave ① Send "Continuously Auto-resolution mode " instruction ST 0100011 ② Wait to complete 1st Auto-resolution mode measurement.( max. 180ms ) ③ Read measurement result 0100011 How to calculate when the data High Byte is "10000011" and Low Byte is "10010000" ...

Page 8

... BH1721FVC VCC SCL GND SDA 0.1µF DVI 0.1µF BH1721FVC VCC SCL 1kΩ GND 0.1µF SDA DVI 0.1µF BH1721FVC VCC SCL GND SDA 0.1µF DVI 0.1µF V2 8/15 Technical Note Micro Controller RESET Reset IC( Push-Pull type ) RESET Reset IC( Open drain type ) 2010 ...

Page 9

... Rise time of power supply: 100µs or less 2. Please do the application design to secure Reset section 1µs or more after the reclosing of the power supply. www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved 1kΩ BH1721FVC VCC SCL GND 0.1µF SDA DVI C1 : 1µF t2 Time to power supply reclosing: 25ms or more 0 ...

Page 10

... C Bus interface, and follow the formally timing chart. SDA LOW SCL STA DAT 2 ) Write Format BH1721FVC is not able to accept plural command without stop condition. Please insert SP every 1 Opecode. Slave Address ST "0100011" Read Format Slave Address ST "0100011" from Master to Slave ex ) High Byte = "1000_0011" Low Byte = "1001_0000" ...

Page 11

... BH1721FVC ●Adjust measurement result for influence of optical window. (sensor sensitivity adjusting ) BH1721FVC is possible to change sensor sensitivity. And it is possible to cancel the optical window influence (difference with / without optical window) by using this function. Adjust is done by changing measurement time. For example, when transmission rate of optical window is 50% (measurement result becomes 0.5 times if optical window is set), influence of optical window is ignored by changing sensor sensitivity from default to 2 times Sensor sensitivity is shift by changing the value of MTreg (measurement time register) ...

Page 12

... C bus Interface SDA Terminal SDA, SCL Reference Voltage Terminal And DVI Terminal is also asynchronous Reset 150kΩ for internal registers.So that please set to ' least 1µs, DVI <= 0.4V ) after VCC is supplied. BH1721FVC is pulled down by 150kΩ while DVI = 'L bus Interface SCL Terminal 12/15 ...

Page 13

... BH1721FVC ●Package Outlines A E Production Lot No. code ●Optical design for the device 0.8 mm Min.0.4 mm Min.0.4 mm Min.0.4 mm Min.0.4 mm www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved. WSOF5 (Unit: mm) 0 area (0. 0.3 mm) Please design an optical window to have the focused light within this area. ...

Page 14

... BH1721FVC ●Notes for use 1) Absolute Maximum Ratings An excess in the absolute maximum ratings, such as supply voltage ( Vmax ), temperature range of operating conditions (Topr), etc., can break down devices, thus making impossible to identify breaking mode such as a short circuit or an open circuit. If any special mode exceeding the absolute maximum ratings is assumed, consideration should be given to take physical safety measures including the use of fuses, etc ...

Page 15

... BH1721FVC ●Ordering part number Part No. Part No. WSOF5 1.6±0.05 (0.8) (0.3) 1.0±0. 0.1 S 0.5 0.22±0.05 0.08 M www.rohm.com © 2010 ROHM Co., Ltd. All rights reserved Package FVC: WSOF5 <Tape and Reel information> Tape Embossed carrier tape Quantity 3000pcs TR Direction The direction is the 1pin of product is at the upper right when you hold ...

Page 16

No copying or reproduction of this document, in part or in whole, is permitted without the consent of ROHM Co.,Ltd. The content specified herein is subject to change for improvement without notice. The content specified herein is for the purpose ...